Phenylhydroquinone is a useful monomer for the preparation of liquid crystal polyesters and speciality resins. The availability of a variety of phenylhydroquinone derivatives would be of interest, for example, for the preparation of new liquid crystal polyesters and specialty resins having a range of properties not possessed by known materials.
Prior art preparative methods are limited in their ability to produce substituted phenyl hydroquinone products, involve the use of expensive chemicals as starting materials and employ exotic chemical conversions. For example, phenylhydroquinone has been prepared by reaction of the diazonium salt of aniline with parabenzoquinone, followed by catalytic reduction of the intermediate product, phenylparabenzoquinone, to produce phenylhydroquinone.
An alternate method reported in the literature for the preparation of phenylparabenzoquinone involves the reaction of benzene with parabenzoquinone in the presence of equimolar amounts of palladium acetate. This process only gives low yields of the desired intermediate, phenylparabenzoquinone, and is also quite expensive because large amounts (equimolar quantities) of the palladium acetate promoter are required.
There is, therefore, a need for high yield, reduced cost synthetic methods for the preparation of phenylhydroquinone, and derivatives thereof.